Electric meter.



, w. H. PRATT.

ELECTRIC METER. APPLICATION FILED MAR. H i, I914- Patented Mar. 28,1916.

2 SHEETS-SHEET 1- Fig. l.

Witnesses:

Inventor" Wil Iiarn H. Pratt,

M ML

His fittorneg.

W. H. PRATT.

ELECTRIC METER.

APPLICATION FILED MAR. 18, 1914.

Patented Mar. 28, 1916.

2 SHEETSSHEET 2.

Inventor William H. Pratt,

" His fittol ne g.

Witnesses: $15

7 meter embodying the novel features or my STATES- PATENT @FFICE.

WILLIAM H. PRATT; or LYNN, MASSACHUSETTS; Asst COMPANY,;ACOBPORTION' OF NEW YORK. j I

. ,v .3 Specification 011' Letters Patent.

--'nnnornio METER} y *japiin saaa fi ealnarcn18,1914,'seriainasaasea To all iokom it ifiay cohcerii. K

Be it known that LIVILLIAM H. PRATT, a

the following is a" sp jifi a o- My imam-ion t to electric meters.

The objects of my invention "are'to 'generally improve the construction of electric meters and to provide a meterhaving comparatively few parts, and one1n"Whic h the operative elements are easily assembled and conveniently exposedfor inspection and repair, and further one of pleasing, neat and symmetrical i'external appearance. These features'I at ta'in by, providing anovel form and, ai'rang'einentfof terminal chamber, an improvedterminal construction and a novel type of damping magnet which 1s peculiarly advantageous for use in electric meters. r Other specific objectsof my invention will be noted hereinafterx I n The features .,of my invention which I- deem patentably novel are definitely pointed out in the claims appended hereto. v The construction andmethod ofoperation of an induction :elect-ric meter'embodying the novel features of my invention will be understood from the followingdescription taken in connection with the accompanyln'g drawings in which i Figure. 1 is a sectional'end elevation of a invention; Fig. 2 is a front elevation of the meter removed from its inclosing casing; Fig. 3 is a rearelevation of the meter also cross section illustrating my novel terminal construction. 1 I The operative elements of the meter are.

mountedupon a; central'supporting member 10 of magneticniaterial. 'The peripheral.

lar, as shown in Figs-2 and 3. A terminal chamber 11 is integrally'secured tothe support ng member and is posit oned entirely to Fig.}f1"'ofithe"'drawings. f The te minal chamber isfciretilar vin shapefcontorming and has a trough-like recess in Which the terminals are located. The interiorwall of the terminal cham beris' provided With four circular openings 12. A strip of insulating material 13, such as fiber, is arranged on each side of the I 'terior Wall. T hese' strips of insulating material are provided With circular openings of smaller diameter than the openings 12 and is provided with bent portions or flanges 15 engaging the outside surface of'one of the savanna GENERAL minerals I Patented Mar. ZSJQM; 7

"with the outline of the supporting member, I

concentrically arranged with the latter. A metallic sleeve 14 passes through the regis- 7 tering openings 'in'the fiber strips and in the interior wall of the supporting member and insulating strips ,and otherfianges 16 engaging the outside surface of the other in} Fingers ,19 are integrally attached the coils of themeter, is arranged between the head of the'nut 1S and the flange 16', and

'sulating strip. A bolt 17 passes through the sleeve and is provided with a nut 18.

to the sleeve 14 and are adapted to be another conductor 21, adapted for ,connection to the line, is arranged between the head of the bolt 17"and the flange 15. It will thus be observed that all the parts of this terminal are rigidly secured together by tightening the bolt 17 The'inagneticlelements of the meter comprise a potential core 25 and a series or current core 26." These cores consist of the usual bundle of lami'nations of magnetic material." The potential core 25 is generally U-shaped with its legs inwardly inclined, as} 7 clearly shown in Fig. 3' of the drawings. A

bundle of laminations 32'is mounted between the" ends of the two legs of the core A piece of insulating material 33,'s'uch as horn fiber, separates the laminations 32 from the laminationsflof' the potential core. The laminati'ons 32 are bound together and held in position by clamping strips 3i ffnonoutline of thesu-pporting member iscircumagnetic material. A potential coil 27 is mounted upon' eacli. leg ofthe core 95,and'is held llrpOEi llilOn by means of tongues 281 slit from the"outside-laininations of the core.

The 'core' 25 is secured to" the supporting member 10 by a bolt '29."

ounted upon the center leg 15. I V V m and positioned in the space between the center and outside legs. The poles of the poten like a figure 8 is mounted to surround each of the legs of the potential core with a inetallic short circuit. This phase lagging plate is made from a single punched blank,

as will be clearly seen by reference to Fig.

at of the drawings. Attaching members 36 are integrally secured to the phase lagging plate and are adapted to be attached to the rear of the potential core by bolts 37, as illustrated in Figs. 1 and 3 of the drawings. The position of the phase lagging plate can be adjusted by providing slots 49 in the attaching members 36, as illustrated in Fig. 4.

A friction compensating plate 38 of the same general construction as the phase'lagging plate 35 is operatively mounted below the latter plate. The two openings of the friction compensating plate also surround the legs of the potential core. The friction compensating plate has an attaching member provided with slots .39. The attaching member is secured to the front of the supporting member 10 by means of bolts 40, and the position of the plate 38 can be ad justed by loosening the bolts 2L0 andmanipulating acotiperatively positioned lever 41, as will be evident from an inspection of Figs. 2 and 4: of the drawings.

A disk armature l2 of aluminum or other suitable metallic material is secured to a rotatably mounted shaft 43. The bearings for the shaft 4:3 are suitably carried by the supporting member 10. The shaft drives through suitable ratio gearing the usual meter register The register. is secured to posts 45 which are integrally attached to the supporting member 10. I

A damping magnet 50 of novel and improved construction is secured by bolts 51 to the supporting member 10.. The magnet has. a continuous outer ring and a plurality of inwardly extending members 52 integrally secured thereto. The inwardly extending members 52 are arranged in pairs and have an air gap between the members of each pair in which the armature 42 is adapted to rotate. The outer continuous ring and inwardly extending members of the magnet are cast as an integral structure, and the air gap between the inwardly extendingmemhers is made by sawing through these members. In magnetizing themagnet, coils are suitably arranged upon the inwardly projecting members so that poles of alternate polarity are provided on each side of the armature. This arrangement of the poles of the magnet is indicated in Fig. 2 of the. drawings by reference letters N and S. It. will thus'be seen that I have provided a cast magnet having a plurality of pairs of poles, with poles of alternate polarity oneach side of the rotating element 42. This construction of the damping magnet enables the magnet to be secured to its supporting member at its neutral points. Furthermore, the alternate arrangement of north and south poles on each side of the damping member provides a greater eddy current loss and hence a more efl'ective damping.

It will be observed from the foregoing description that all of the operative ele* ments of the meter are mounted one single supporting member. The motive elements are secured to one side of the supporting member, as shown in Fig. 3 of the drawings, and the register and damping magnet are secured to the other side of the member, as shown in Fig. 2 of the drawings. A casing such as illustrated in Fig. 1 is provided for inclosing the supporting member and attached operative elements. comprises a rear inclosing member 60 having a keyholed plate 61., of the usual type, secured thereto for supporting the meter. A plate 62 is also secured to the rear in.- closing member and assists in supporting the meter. The rear inclosing ,member 30- is'constructed of suitably rigid material, such for example as relatively heavy sheet metal, and the supporting member 10 fits.

very snugly in this inclosing member so that the supporting member and. the meter elements thereto attached are in fact supported-by the rear inclosing member 60. The meter is adapted to be mounted in position by means of the keyholed plate 61 and the plate 62, the ends of the latter extending.

beyond the periphery of the member 60 so as to provide supporting extensions. The rear inclosing member 60 is also provided with pins 63, which have enlarged heads adapted to register with recesses 64; in the supporting member 10.. A front inclosing member 65 having a circular glass window 66 is secured to the rear inclosing member 60 by means of the pins 63 and bayonet j oint This casing slots in the member 65. A plate 67 having suitable openings, 68 for leadingsin wires 18 arranged to close the terminal chamber.

It will thus be observed that'the casing-of the-meter is cylindrical in shape and entirely symmetrical. The terminalehamber is-located within the.casing:-and=iis adapted to be removed as a unit. withtthe supporting 'member and other attached elements from the casing. This is of particular advantage, s1nce it enables a quick and convenient inspection of the operative elements of the meart. Further, theapplication of the novel features of my invention to other types of electric, meters than that .herein illustrated will be obvious, and I do not, therefore, de-

sire to be limitedto the specificconstruction or to the particular type of meter herein illustrated by way of example I, accordingly, aim to cover in the appended claims all applications and modifications of my inventionwithin thespirit and scope of the same. i

What I claimas new and desire tosecure by Letters Patent of the United States, is,

1. In an electric motor meter, a rotatable element, and a damping magnet having a plurality of poles of alternate polarity arranged on one side of said element and a plurality of cooperating poles of alternate polarity arranged on the other side of said element and a member magnetically and mechanically connecting said poles thereby forming a unitary magnet structure.

2. In an electric motor meter, a rotatable element, a clamping magnet for said element comprising a continuous outer member and a plurality of inwardly extending members uni ed in a unitary structure, said inwardly extending members being arranged in pairs with an air gap between the members of each pair whereby said magnet has a plurality of pairs of poles.

3. In an electric motor meter, a rotatable element, a damping magnet comprising a continuous outer member and a plurality of inwardly extending members united in'a unitary structure, said inwardly extending members being arranged in pairs with an air gap between the members of each pair whereby said magnet has a plurality of pairs of poles, and means whereby said magnet can be attached at its neutral points to a fixed part of the meter.

4; In an electric motor meter, a rotatable element, and a damping magnet for said element comprising a continuous outer ring and a plurality of inwardly extending members arranged in pairs with an air gap between the members of each pair whereby said magnet has a plurality of pairs of poles.

5. In an electric motor meter, a damping magnet comprising a continuous outer ring;

and a plurality of inwardly extending'mem bers arranged in pairswith an air gap between the members of each pair whereby said magnet has a'plurality of pairs of poles},

a disk rotatablymounted'in the air-ygiaps,

and means whereby said'magnet can be attached at, its neutral points to. a fixed part of the meter.

6. In van electric motor meter, a substan-;

.tially circular supporting member, a terminal chamber forming extension arranged: within the peripheral outline of said meme, her and attached thereto, meter elements operatively mounted on said member so that the member and all of the attached elements can be removed as a single unit from a meter casing adapted to inclose said member and all of said elements.

7. In an electric motor meter, a substan tially circular magnetic supporting member, a rotatably mounted disk armature extending through said member, motive elements mounted on one side of said member, a damping magnet and a meter register operatively mounted on the other side of said member, a terminal chamber forming extension integrally attached to said supporting member and arranged within the peripheral outline of said member, said member and all of the attached elements being so arranged that they can be removed as a single unit from a meter casing adapted to inclose the member and all of the attached elements.

8. In an electric meter, a supporting memher, a terminal chamber forming extension arranged within the peripheral outline of said member and integrally attached thereto, said chamber having a wall with a plurality of holes therein, a strip of insulating material on each side of said wall and having holes therein concentrically arranged with the holes in said wall, a sleeve extending through each of said holes and having flanged end portions adapted to engage the outside surfaces of said strips, and a bolt passing through said sleeve and having a nut thereon.

In witness whereof, I have hereunto set my hand this fourteenth day of March, 1914.

WILLIAM H. PRATT.

Witnesses:

JOHN A. MCMANUS, J r., FRANK G. HATTIE.

Copies of this patent may be obtained for five cents each, by addrssing the qommissioner of Iatents. Washington, I). C.

i 191 6, up0n the epplicztioh cfWilliam H. Pratt, of Lynn, Massachusetts, for an improvement in Eleetrlc'Meters, an error appears in the printed specification I reqfifi'ing correction as followsz: Page 3, line 3l, claim 2, for the Word clamping reQd dam ing; and that thesaid Letters Patent should be read with this correction Signed and ealed this 25th day of April, A. D., 1916.

SEAL A T J. T. NEWTON,

C 1. 171.264. I Acting Commissioner of Patents.

Correction Letters Patent No. 1,177,444.

' It, is hereby certified that in Letters Patent No. 1,17 7,444, granted March 28,

therein -that the same-may conform to the record of the case im the Patent Office. 

